As one of basic components of a railway vehicle, the coupling buffer has the advantages of rapidly connecting and disconnecting railway vehicles, transmitting vehicle tractive force, and improving vehicle safety and comfortability.
The coupling buffer essentially comprises a coupling device, a squashing device, a buffer device, and an overload protection device. The coupling device has the function of connecting and disconnecting railway vehicles; the squashing device has the function of protecting vehicle body and passenger safety in emergency; as a coupling buffer, the buffer device has the function of improving the longitudinal impulse performance and improving vehicle safety and comfortability; when railway vehicles suffer from great longitudinal impact, the overload protection device facilitates the coupling buffer to separate from vehicles, and further facilitates other energy absorbing devices on vehicles to come into play. As an important energy absorbing device in the coupling buffer, the buffer mainly takes part in longitudinal energy absorption in the normal running process of railway vehicles. Many existing buffers realize the function of energy absorption by means of compressing internal elastic components, while a buffer itself is connected to the mounting seat by means of a rotation axle so as to realize the function of rotation of the coupling buffer. The mounting seat is connected to vehicle body by means of an erection bolt or the overload protection device so as to transmit longitudinal load.
At present, commonly the overload protection device is arranged on the outside of the coupling buffer, directly connecting the coupling buffer with vehicle body, and facilitates the coupling buffer to separate from the vehicle body once it comes into play. An existing railway vehicle coupling buffer mainly consists of a fixed-type housing (the mount), a compressible elastic element and a shell bearing the elastic element. For realization of overload protection inside the buffer, one method is to break the connection between the mount and the shell, and the other method is to break the connection between the shell and the elastic element. At present, the first method is widely used; but this method requires for small size of the shell and inside components, and requires the shell to break out of a hole at the rear of the mount of the coupling buffer successfully. However, the mount is limited by design of the vehicle body, and it is difficult to enlarge the hole size. A high-performance buffer usually has a large volume, and is unable to break out of the mount successfully. Hence, the application scope of the first method for realization of overload protection is greatly restricted. For integrating the overload protection device, the existing high-performance buffer shall ensure the number of components breaking out of the mount is reduced; the existing mode cannot be used for ensuring all components inside break out of the mount, instead, a few components breaking out of the mount can achieve the objective of overload protection.